1. Field of the Invention
This invention relates to a catalytic process for the preparation of polyamides. More specifically this invention relates to a novel catalyst consisting of at least one transition metal attached to at least one ligand containing electron withdrawing substituents. In one embodiment, these electron deficient catalysts are useful for the production of nylon-3 and nylon-3,X polymers and copolymers of increased molecular weight.
2. Description of the Prior Art
Polyamides are polymers which contain recurring amide groups (CONH) as integral parts of the main polymer chain. Polyamides are generally formed by condensation polymerization or by addition polymerization. The parameters for these processes as well as the specific monomers suitable for polyamide formation are known to those skilled in the art.
Polyamides are frequently referred to as nylons. A common form of shorthand, which serves to identify aliphatic polyamides, involves the use of numbers that signify the number of carbon atoms in the respective monomers which were polymerized to form the polyamide. For Example, nylon-6 results from the polymerization of caprolactam and nylon-6,6 is formed by the polymerization of hexamethylenediamine and adipic acid.
In part, the instant invention pertains to the production of nylon-3 and nylon-3,X polymers and copolymers. It is known that nylon-3 can be prepared from various monomers. For example, U.S. Pat. No. 4,283,524 describes a process where nylon-3 is prepared from the ammonium salts of alpha,beta-unsaturated monocarboxylic acids. U.S. Pat. No. 2,691,643 teaches that nylon-3 can be prepared by the thermal condensation of beta-amino propionic acid. U.S. Pat. Nos. 3,629,203 and 3,499,879 relate to the preparation of nylon-3 by the condensation reaction of acrylonitrile. U.S. Pat. No. 2,749,331 teaches that nylon-3 can be prepared from acrylamide. However, nylon-3 polymers and copolymers produced by these processes are generally characterized by very low molecular weight.
An object of the instant invention is a catalytic process useful for preparation of polyamides.
A further object of the instant invention is a catalytic process useful for producing nylon-3 polymers and copolymers of increased molecular weight.